Improvement in hand-pieces for dental drills



J. W. GILBERT.

HAND PIECES Fon DENTAL DRILLS.

patented 13.80.14.1875.'

I JV VEJV TOR UNITED STATES PATENT OEECE.

JOHN W. GILBERT, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO SAMUEL S. WHITE, OF SAME PLACE.

IMPROVEMENT IN HAND-PIECES FOR DENTAL DRILLS.

Specification forming part of Letters Patent No. 171,009, dated December V14,1875 application tiled November 19, 1874.

CASE B.

To all whom it may concern.-

Be it known that I, JOHN W. GILBERT, of the city and county of Philadelphia, in the State of Pennsylvania, have invented certain new and useful Improvements in Dental Drills, of which the following is a specification y My invention relates to a novel method of securing a dental burr, drill, or other tool in the power -driven revolving chuck or toolholdcr of the hand-piece of a dental engine. The subject lnatter claimed is hereinafter specified. -1

ln the accompanying drawings, Figure 1 represents an axial section through the handpiece; Fig. 2, a similar view of a portion of the chuck ou an enlarged scale. Fig. 3 is a similar section on the line e z of Fig. 2, with the tool inserted in the chuck; Fig. 4, a detail view of a portion of the tool; Fig. 5, a transverse section through the instrument, on the line o o of Fig. 1; Fig. 6, a similar section, on the line w w of said figure; Fig. 7, a similar section on the line a; a: of said ligure; Fig. 8, a like section, on the line y y of said flgure.

A powerdriven shaft, A, revolves in suitable bearings in a tubular casing or handpiece, B. The forward end of the revolving shaft is perforated axially for the receptionof a tool, C, which has a shoulder, c, turned on its end. A 1ug,c, projects radially from this shoulder. The tool is inserted in its socket a, and pressed in until the lug comes opposite a slot, al, in the wallof the tool-holder, when it is turned partially around on its axis, so as to bring this lng behind the shoulder of the toolholder. (See Fig. 3.) A spiral spring, a2, in the tool-holder tends to force the tool outwardwhen released. A locking slide or bolt, D, movable endwise on the tool-holder, is protruded whenever released from backward pressure by a spiral spring, E, on the shaft A. The locking-bolt D, when thrown forward, moves across the opening of the slot al, through which the lug is passed, and prevents the stool from turning. (See Figs. 1 and 2.) The slide may be retracted by pressing on its roughened surface with the thumb nail through a slot, b, in the casing ot' the hand-piece, the surface o f the slide being roughened to aid this operation.

I am thus, by my invention, enabled to lock a tool securely in place, to prevent it from becoming loosened, either by a reversal of the movement of the engine,A or by a pushing or pulling strain.

I claim as of my own invention- 1. The combination of the slotted toolsocket, the interlocking slide movable endwise and externally on the tool-holder, and the locking-spring encircling the tool-holder.

2. The combination of the casing, the powerdriven shaft rotating in bearings therein, and perforated and slotted to form a tool-holder, a tool provided with a radial lug on its shank, the spring encircling the shaft, and the lockl' ing-slide actuated by said spring, to lock the lug on the tool-shank in the slot in the toolholder, substantially as hereinbefore set forth.

3. rIhe combination ot' a dentaltool socket, formed substantially as described, and alockingslide operating to close the path by which the lug on the tool enters a shouldered recess of said socket, substantially as hereinbefore set forth.

In testimony whereof I have hereunto subscribed iny name.

JOHN W. GILBERT. Witnesses:

J. A. B. WILLLAMs, J. W. DE BAEGER. 

